Floyd, keep in mind that SR is like Mt. Gox is that it's more of a middleman between buyers and sellers, though the guy running the site is a seller himself. It's very likely that he doesn't sell any of those drugs you quoted, but one of the other sellers wanted to offer it and so he needed to add the relevant pages to the site.
I'll keep that in mind, and perhaps I should have layered my comments a bit better.
Nonetheless, and in the final analysis all three parties, seller - buyer - middleman are involved and therefore share in some of the moral and legal implications of their actions. I think this is particularly relevant in regards to this system which from what I've seen doesn't even make as much effort as the pron industry in preventing underage access to, what should be, adults-only products. And even then, there are other concerns about true quantities, dosage and ingredients / adulterants of already potentially fatal narcotics.
As someone passionate about drug legalization and from the apparent level of higher-than-average intelligence I see on this board, it needs to be clearly stated exactly what the ramifications are of engaging in this business model, no matter what your particular role in it may be.